Universal doesn't have trailers on their discs? But don't they have those stupid start up previews? And worse Universal usually doesn't have a link to them from the main menu like Disney does with the Sneek Peeks section. This actually sounds like a really cool project. I would be interested in seeing those start up previews included as well, but that way they would be more organized and not play when you're excited to watch something else. The only thing about dvd previews I hate is when they automatically start up for a dvd playing. It would be cool to see all the previews for the Disney Platinum editions included on one disc, for example.

For trailers that are missing.
Fifth Element: I think there are plenty included for the Regions outside 1.
Harry Potter: Azkeban only had one, the disc was missing the Choir Song teaser. Goblet had the cool one with shots of the trio from all four years but there should be others. Menu design for movie 4 sucked.
Dragonslayer: early 80's movie with nothing else on the dvd, not even the trailer.
Dune: Did the new R1 extended edition have the trailer, I heard it didn't. A widescreen vhs tape did plus a preview for other features with the theme "Science Fiction is now more popular than ever."